Dressing attachment for screw thread grinders



[NVE N TUI? A.V M. DRAKE ET AL Filed Maron 4, 1952 4 `sheets-sheet Nov. 8, 1932.

DRESSING ATTACHMENT FOR SCREW THREAD GRINDERS Nov. 8, 1932. A. 1M. DRAKE ET AL 1,836,796

DRESSING ATTACHMENT FOR SCREW THREAD GRINDERS Filed March 4, 1952y 4 sheets-sheet 2 mvsnroh A. M. DEA/z.:

BY/VJCeow y* M5 treni' Nov. 8, 1932 A. M. 'DRAKE ET AL 1,886,796,

DRESSING ATTACHMENT FOR SCREW THREAD GRINDERS Filed March 4, 1932 4 Sheets-Sheet 3 /NVE/vrun A. M. DEA/(E B"/V. .CEW Y Arron/1E Nov. 8, 1932. A. M. DRAKHE ET Al. 1,886,796

DRESSING ATTACHMENT FOR SCREW THREAD GRINDERS Filed Marcn4, 1952 4 sheets-sheet 4 /NwmTon A, M. DEA KE By NJ Ceow ,AM W Tron/v5 Patented Nov. s, i932 UNITED STATES rATENr ort-'ica` ALBEN 1r. nRAxE Ann NORMAN J. cRownY, or wnsr HARTFORD, commencer, AssreNoRs 'ro PRATT af. 4.WHITNEY comm, or HARTFORD, ooNNEcrIcur, A ooR- PORATION OF JERSEY DRESSING .A..I'.".I..B.GIBI:ISEI EN'T FOR SCREW THREAD GRINDERS Application led March 4, 1932. Serial No. 590,786.

This invention relates to a dressing device for abrasive wheels and particularly to an attachment or device for dressing a multiple grooved wheel to a. high degree of precision,

provide convenient, accurate and rapid means to dress the contour of a multiple grooved grinding wheel. j Another object of the invention is to provide-a slide or carriage having two obliquely disposed slidably mounted dressing tools thereon adapted to be passed over theA work engaging surfaces of a plurality of ridges on a wheel, the dressing tools being movable with the slide or carriage for precision indexing movements to successive positions along the cylindrical surface of the wheel.

One feature which enables us to accomplish the above named objects is that a plurality ofgraduated stops are provided movable successively into operative position to limit the movement of the slide carrying the dressing tools in one direction, means, preferably hydraulically operated, being ernployed to force the slide in one direction to successively position the dressing tools, to retain them in their indexed position during dressing movements of the tools over the wheel, and return them to their initial positions.

With thelabove and other objects in view, our invention includes the features ofcoustruction and operation set forth in the following specification and illustrated in the accompanying drawings. Y

In the accompanying drawings annexed hereto and 'forming a part of this specification, we have shown our invention embodied in' a dressing attachment for thread grinding machines having a conventional or standard screw thread form, but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a plan view of a complete dressing attachment made according to the present invention, parts being shown in section to more clearly indicate their construction.

Fig. 2 is a side elevation of the complete dressing attachment shown in Fig. l, a part being broken away to more clearly show the positioning or indexing means for the slide carrying the dressing tools. c l

Fig.v 3 is a vertical sectional view of the complete dressing attachment taken upon the planes of the broken line 3-,3 of Fig. 2.

Fig. 4 is a detail-view of the manually operated cam means for controlling the position of the slide actuating mechanism. y

Fig. 5 is a detail view of the extended end of the adjusting screw for the dressing attachment shown in Fig. 2, and

Fig. 6 is a front view of the parts shown l which is now deemed preferable, but it is tov be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briey and in its preferred aspect, our invention may include some or all of the following principal parts:` First, a base by means of which the complete dressing at tachment may be mounted adjacent the wheel to be dressed with the base lixed in position relative to the grinding machine; second, a saddle movable on the base to adjust the position of the dressing tools directly toward and from the wheel; third, a slide on said saddle movable parallelly to the axis of the wheel to ,be dressed or along the grooved lsurface of the wheel; fourth, dressing tools figures of the drawings, I provide a base 10 by means of which the complete dressing attachment,

16 secured within the saddle 14. 'On the upper surface of the saddle 14 are ways 16 extending parallelly to the axis of the wheel 11 to be dressed within which is slidably mounted a carriage or slide 17 mounting the wheel .dressing tools 18.

In the form of the invention illustrated in the drawings the dressing tools 18 include slidably mounted bars 19 having'at their ends adjacent the wheel 11 diamond or other forms of dressing tools which may be traversed over the work engaging sur,- faces of the wheel 11 by slidable advancing and rearward movements of the bars 19. The bars 19 are individually retained in angular] adjustable'housings 20, the obliquity of which may be adjusted to correspond with the desired conformation of the surfaces being dressed. In order to actuate the bars 19 to traverse the dressing tools 18 over the sur.'

faces of the wheel 11 a hand lever 214is provided pivotally mounted on a vertical axis and havmg a gear 22 thereon, the teeth of which engage rack teeth 23 cut along the face of one of the bars '19. Also engaging this gear 22 is an intermediate gear 24, the teeth of which also engage rack'teeth 25 on the opposite bar 19. oscillatory movements therefore of the handle 21 serve to traverse the dressing tools 18 toward and from the wheelv ing tools 18 to successively advanced lopera-` tive positions. To facilitate that purpose a plurality of stops are provided in the form of end measures 26, the length of these rods or end measures 26 lvarying by increments equal to the desired spacings of 'the successive ridges and grooves on the wheel 11. 'Ihese end measures 26preferably may be mounted within a rotatable holding device or turret 27 which may be rotated manually to successivelybrin the stops 26 into engagement hetween an a utment or side face on the saddle 14 and an adjustable abutment 28 on the slide 17. This construction will be apparent from an inspection of Fig. 3 in which the slide 17 an adjustable bar 29'slidably mounted within the slide 17 which in turn has its opposite end engaging an adjusting means in the form of a screw 30 which maybe rotated to position the dressing tools for proper initial dressing operations. When adjusted the screw 30 may be retained in adjusted position by clamping screw 31. Preferably theend measures are loosely retained individually Within recesses or holes'through the member 27 so that 'they may properly position themselves between the abutments when in operative position.

In order to actuate the slide 17 carrying the dressing tools 18 along the ways 16 in the saddle 14 hydraulic means may be provided. Preferably a cylinder 32 is provided on the slide 17 within whichis apiston 33, the piston4 rod 34 of which is clamped at its outer end to an extension 14@L of the saddle 14. By admitting fluid to opposite ends of the cylinder 32 the slide 17 ma be moved from'on-e eX- treme position to the other to effect dressing operations along the entire face of the wheel 11. In order to admit iuid to the ends of this cylinder 32 a valve 35 is employed preferably of the balanced piston type operating' Within a suitable valve chamber, the central portion of which is provided with a fluid ad mitting opening 36, and from the opposite ends of which Huid may be exhausted through suitable openings 37. By sliding the valve 35 from one position to anotherv within this chamber the slide 17 may be moved to the left or right. In the position of the valve 35 shown in Fig. 3,luid is bein admitted to the right hand end of the cylin er 32. By moving the valve 35'to the left iuid may drain from the right hand end of the cylinder 32 through exhaust open-in 37 and be admitted to the left hand end, t e valve head overrunning the connecting port between the valve chamber and the left hand end of cylinder 32. Admission opening 361to the vvalve chamber may be connected to a supply line 38'and eX- haust openings 37 therefrom to an exhaust connection 39 of any usual or standard types.

Preferably the valve 35 may be controlled by a cam 40 shown more in detail in Fig. 4 mounted upon and oscillated by movement of a hand lever 21. This cam 4() is adapted to engage a projection 41 on a pivotally' mounted lever 42 within the slide 17. 'llh'e free end of this' -lever 42 engages a connecting rod4 43, the opposite end of the rod 43 engaging a reach rod 44 attached at its far end to an extended end of, valve 35 which extends throughr` the end wall of the slide 17 There are three positions of this cam 40, that shown being the one in which the slide 17 is 'bein forced toward the right t hold the slide 1 in predetermined position for one of the dressing operations. In this position of the valve which may be maintained by a suitable spring 47 the rods 19 carrying the dressing tools 18 are reciprocated by movement ofthe handle 21 to effect the dressing operations over the Work engaging surfaces of the wheel 11. This movement of the handle 21 'causes an inoperative segment of the cam to be adjacent the valve operating lever 42 so that no movements of the valve 35 are elected and the full pressure is exerted by the slide 17 against an end measure 26 to positively hold the slide -17 in its extreme limiting position. In order to release the pressure of the slide 17 against its end measures 26 to permit indexing to an adjacent position the handle 21 is brought to a forward position so that the projection 41 on lever 42 engages a recess v45- in the cam 40.

In this position of the cam 40 the valve 35 is held in neutral or central position and pressure on opposite sides of the piston 33 is equalized, asboth ends of the cylinder 32 are open to the exhaust ports 37. Thispermits free movement of the turret member 27 carrying the end measures 26 about its axis.

With another end measure 26 rotated into operative position the handle 21 is again moved back to the position shown in Fig.' 4 whereupon lthe dressing attachment slide v17 is advanced to the right so that the dressing tools 18 may be again operated in their new indexed position. This alternate indexing and dressing operation may be continued for v as many positions as there are grooves formed in the periphery of the Wheel 11. In order to return the slide 17 to its extreme ,left position the handle 21 is brought to itsextreme orward position so that the lever 42 engages the second recess 46 in the cam .40 which forces the valve 35 to its extreme left hand position, thus admitting :fluid to the left hand end of the cylinder 32 and forcing the slide 17 towardthe left.

As shown in Figs. 2 and 3 the end measures "26 are positioned parallel to each other and spaced equidistant from the center of the rotatable member 27 within which they are loosely retained. In .order to rotate this member 27 to successively move the dilerent end measures 26 to their operative positions a hand lever 5() is provided having a spring pressedpawl 51- engaging a ratchet wheel 52 carried by the shaft 53 mounting the rotatable member 27. 'This hand lever 50 may have its oscillatory movements limited by abutments 54 and 55 preferably in the form of adjustable screws sothat the proper angular movement ma be given the hand lever 50 to bring the di erent end measures 26 successively into position. AAlso vs. detent lnay be provided for each indexed position of the rotatable member 27 in the form of a spring pressed plunger 56 engaging spaced conical In order to indicate the angular position to which the end measure retaining member 27 is rotated a dial 57 may be provided having graduations thereon and mountf i on the shaft 53 outside of the frame.. Adjacent this dial'57 is-a zero mark and pointer 58, indicating what particular end measure 26 is in operative position. To advance the dressing attachment toward the periphery of the wheel as the wheel 11 is successively worn away a ratchet wheel 6() may be mounted upon the rear end of the depressions in one face of this member 27. j

shaft 61 carrying the adjusting screw -15- which may be engaged by a pawl 62 carried by one arm of thebell crank member 63. By oscillating this bell crank member 63 the shaft 61 and screw 15 may be slightly rotated to advance' the base 10 of dressing attachment in either direction toward or from the wheel 11..

What we claim is:

1. A wheel dressing device comprising in combination, a base adapted to be mounted adj acent'a wheel to be dressed, a slide thereon, dresser carrying members movably Y mounted thereon, means to move said slide to pos1t1on said dressers for successive operatlons onsaid wheel, a plurality of means to limit the movement of said slide in one di- -rect1on, and means to successlvely move said limiting means into operative position. 2. A wheel dressing device comprising combination, a base adapted to be mounted adjacent a wheel to be dressed, a slide there on movable parallelly to the axis of the Wheel being'dressed, dresser carrying members movably mounted thereon, hydraulic meansv to move said slide to position said dressers for successive operations on said wheel, a plurality of graduated means to limit the movement of said slide in one -direction, and manual means to successively move said limting means into operative position.

lll@

3. A wheel dressing device comprising in combination, a base adapted to be mounted adjacent a wheel to be dressed, a slide thereon, angularly adjustable heads on said slide, dresser carrying bars movably mounted within said heads, means to move said slide to position said dressers for successive operations on said wheel, a plurality of graduated stops to limit the movement of said slide in one direction, and means to successively move said stops into operative position.

combination, a base adapted to be mounted adjacent a wheel to be dressed, a slide there- 4. A wheel dressing'device comprising in.

on, dresser carrying members movably l mounted thereon, means to move said slide `to spaced indexed positions to position said dressers forv successwe operations on said wheel, a plurality of graduated stops to limit the movement of said slide in one direction, a

rotatable member carrymg an annular series of stops thereon, and means to rotate said rotatable member to move said lstops to successive operative position to limit movement of said-slide. A

5. A wheeldressing device comprising in combination, a base, a slidethereon movable parallelly to the axis of the wheel being dressed, dressing tools movablyT mounted on -said slide, a hand'lever for operating said dressing tools, means to move said slide to successive indexed positions, and means operated by said hand lever to control said inflexing movements of said slide.

6. A Wheel dressing device comprising in combination, a base, a slide thereon movable parallelly tothe axis of the wheel being dressed, heads'gadjustably mounted Within said slide, dressing tools movabl mounted Within said heads, a hand lever or operating said dressing tools, means to move said slide to successive indexed positions, means to limit the movement of said slide to successive operative positions, and means op.

erated by .said hand lever-to control said indexing movementsof said slide.

In testimony whereof, We hereto ax our signatures.

' ALBEN M. BRAKE,

' NORMAN J. CROWEY. 

